JPS6165334A - Specification system for start address - Google Patents

Abstract

PURPOSE:To improve the degree of freedom of programming by providing a control part with a start address table capable of address rewriting, and specifying a fixed address and an address of the table according to the cause of interruption and specifying a start address. CONSTITUTION:Interruption causes #1 and #2 are inputted to an interruption cause register 10 and also inputted to an OR circuit 11 to obtain select signals of selectors 13 and 14 through an interruption register 12. Flag signals of respective cause-classified bits of the interruption cause register 10, on the other hand, are all stored in the high-order digit bits of a start address register 15. The start address table 16 is retrieved according to addresses indicated by the interruption register 10 and respective fixed addresses. Gate circuits 17-1, 17-2, and 17-4 select the respective fixed addresses and an address of the start address table 16 with bit signals showing whether the start address table is used or not.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for specifying a start address specified by an interrupt in a data processing device operating under microprogram control.

Data processing device f that operates under microprogram control
C. The microprogram is stored in control storage.

When an interrupt cause based on a microprogram occurs, this data processing device converts the control information address of the controller storage that is being used appropriately to the start door address due to the interrupt cause, and performs processing. ing. Generally, the same amount of addresses are used for the star 1 to addresses. There was a desire to change this fixed address to a variable address.

[Conventional technology]

The method of specifying the start address described above is performed as shown in FIG. That is, the interrupt status for each interrupt cause is held in the interrupt cause register 1, and each bit of the interrupt cause register 1 detects the occurrence of an interrupt in the interrupt cause circuit 2, and operates the selector 3 in response to this detection signal.

When a normal interrupt does not occur, the counter 5 sequentially processes the register 4 indicating the address of the control storage 6 based on the control information of the control storage 6.

If an interrupt occurs, as described above, selector 3
operates and switches to interrupt address register 7,
The program is taken out from the control storage 6 and processed using the address in the address register 7 as the interrupt start address.

Conventionally, the address stored in this interrupt address register 7 is a fixed address.

[Problem that the invention seeks to solve]

In the above configuration, the start address is fixed, and when creating a program, you only need to prepare a sufficient address range in the control storage for interrupt processing, but this is also wasteful. There's a problem.

On the other hand, if the address range is lossless at the time of creation, and if there is a change in interrupt handling, this program will
It becomes impossible to give consecutive addresses. Therefore, it becomes troublesome and inconvenient in terms of programming, device operation, and maintenance.

[Means for solving problems]

The present invention provides a start address designation method that eliminates the above-mentioned problems and provides a high degree of freedom in programming. This means is provided in a data processing device that is equipped with a control storage and a control unit and that specifies a fixed address of the control storage depending on the occurrence of an interrupt cause, in which the control unit is provided with a start address table that allows address rewriting. The fixed address and the table address are selected according to the cause of the interrupt using a star 1 addressing method.

[Effect]

A start address table is provided in the control section, and the addresses in this table are configured to be rewritable, and the start address is specified by selecting a fixed address or a double address depending on the cause of the interrupt.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram of an embodiment of a start addressing system according to the present invention. The same parts are denoted by the same reference numerals throughout the figures, and their explanations are also omitted.

Interrupt cause #1. #2 is input to the interrupt cause registers 1O-LIO-2, respectively, and is also input to the interrupt cause register 11-LIO-2.
1.11-2, interrupt register 12-1.1
2-2, it becomes a selection signal for selectors 13 and 14.

On the other hand, the flag signals of each bit for each interrupt cause stored in the interrupt cause register 10-1.10-2 are the upper bits of the start address register 15-1. ). A conventional fixed address is stored in the lower bits of the start address register 15-L 15-2, and rDJ shown in the most significant bit is a bit that indicates whether or not the start address table is used. When it is unused, it is "0" when it is used.

The upper and lower pins of the start address registers 15-1 and 15-2, ie, the pins excluding the highest bit, become the addresses selected by the selector 14. The selector 14 is activated by the selection signals of the interrupt registers 12-1 and 12-2 mentioned above.
For example, start address register 15-1.15-2 is selected.

Therefore, the start address table 16 will be searched at the address indicated by the interrupt cause register 10-1, 10-2 and each fixed address. Improved start address register 154.15-2
and the contents of the start address table 16 are stored in advance.

Gate circuits 17-1, 17-3 and 17-2.17-4
selects each fixed address (lower bits of the start address register 15-1, 15-2) and the address of the start address table 16 by the "D" signal. For example, start address register 15-1
Fixed address when rDJ is logic "1", logic "0"
When this happens, the address of the start address table 16 is output. This output is passed through the output circuit 184.18-2 to the selector 13 as the selected signal. Incidentally, the selector 13 is inputted with the register 4 indicating the address of the control storage during normal use as described in the conventional example, as well as the selection signal.

The selector 13 selects the selected signal consisting of the champion, determines the address, and sets it as the address of the control storage 6.

Therefore, if it is necessary to change the program due to the cause of the interrupt, the program can be changed without any problem by using the start address table.

〔Effect of the invention〕

As explained above, according to the present invention, interrupt processing can be performed using only the start address without considering the area associated with program changes, and the degree of freedom in programming can be increased without reducing the processing speed of the data processing device. It is expensive and has many advantages in operating the processing device.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of the start addressing method according to the present invention, and FIG. 2 is a schematic diagram showing a conventional start addressing method. In the figure, 1, 10-1, and 10-2 are interrupt cause registers, 6 is a control storage, 7 is an interrupt register (fixed address built-in), and 16 is a star l-address table, respectively.

Claims (1)

[Claims] In a data processing device that includes a control storage and a control unit and specifies a fixed address of the control storage depending on the occurrence of an interrupt cause, the control unit is provided with a start address table whose addresses can be rewritten. A start address designation method characterized in that the fixed address and the table address are selected and designated depending on the cause.